(diagnostic
  (schema slovo.diagnostic)
  (version 1)
  (severity error)
  (code UnsupportedEnumPayloadType)
  (message "enum payload variants support only unary direct `i32`, `i64`, `u32`, `u64`, `f64`, `bool`, `string`, or known non-recursive struct payloads")
  (file "<fixture>")
  (span
    (bytes 39 48)
    (range 5 10 5 19)
  )
  (expected "i32, i64, u32, u64, f64, bool, string, or known non-recursive struct type")
  (found "(vec i32)")
  (hint "use a direct scalar/string payload, a known non-recursive struct payload, or keep the variant payloadless")
)